diff --git a/src/com/android/settings/privatespace/PrivateSpaceMaintainer.java b/src/com/android/settings/privatespace/PrivateSpaceMaintainer.java
index 3ec7c9295d0..b5e7692043b 100644
--- a/src/com/android/settings/privatespace/PrivateSpaceMaintainer.java
+++ b/src/com/android/settings/privatespace/PrivateSpaceMaintainer.java
@@ -34,6 +34,7 @@ import android.util.ArraySet;
 import android.util.Log;
 
 import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
 
 import com.android.internal.annotations.GuardedBy;
 
@@ -226,6 +227,26 @@ public class PrivateSpaceMaintainer {
                 HIDE_PRIVATE_SPACE_ENTRY_POINT_DISABLED_VAL);
     }
 
+    /**
+     * Returns true if private space exists and quiet mode is successfully enabled, otherwise
+     * returns false
+     */
+    public synchronized boolean lockPrivateSpace() {
+        if (isPrivateProfileRunning()) {
+            return mUserManager.requestQuietModeEnabled(true, mUserHandle);
+        }
+        return false;
+    }
+
+    /** Returns true if private space exists and is running, otherwise returns false */
+    @VisibleForTesting
+    synchronized boolean isPrivateProfileRunning() {
+        if (doesPrivateSpaceExist() && mUserHandle != null) {
+            return mUserManager.isUserRunning(mUserHandle);
+        }
+        return false;
+    }
+
     private void resetPrivateSpaceSettings() {
         setHidePrivateSpaceEntryPointSetting(HIDE_PRIVATE_SPACE_ENTRY_POINT_DISABLED_VAL);
     }
diff --git a/src/com/android/settings/privatespace/SetupSuccessFragment.java b/src/com/android/settings/privatespace/SetupSuccessFragment.java
index 0b1b9d97763..ebeae7a742d 100644
--- a/src/com/android/settings/privatespace/SetupSuccessFragment.java
+++ b/src/com/android/settings/privatespace/SetupSuccessFragment.java
@@ -84,6 +84,8 @@ public class SetupSuccessFragment extends InstrumentedFragment {
             if (activity != null) {
                 mMetricsFeatureProvider.action(
                         getContext(), SettingsEnums.ACTION_PRIVATE_SPACE_SETUP_DONE);
+                //TODO(b/307729746): Add a test to verify PS is locked after setup completion.
+                PrivateSpaceMaintainer.getInstance(activity).lockPrivateSpace();
                 Intent allAppsIntent = new Intent(Intent.ACTION_ALL_APPS);
                 ResolveInfo resolveInfo =
                         activity.getPackageManager()
diff --git a/tests/unit/src/com/android/settings/privatespace/PrivateSpaceMaintainerTest.java b/tests/unit/src/com/android/settings/privatespace/PrivateSpaceMaintainerTest.java
index 0a2f3d10ecf..1d273263db5 100644
--- a/tests/unit/src/com/android/settings/privatespace/PrivateSpaceMaintainerTest.java
+++ b/tests/unit/src/com/android/settings/privatespace/PrivateSpaceMaintainerTest.java
@@ -21,8 +21,11 @@ import static com.android.settings.privatespace.PrivateSpaceMaintainer.HIDE_PRIV
 
 import static com.google.common.truth.Truth.assertThat;
 
+import android.app.ActivityManager;
+import android.app.IActivityManager;
 import android.content.ContentResolver;
 import android.content.Context;
+import android.os.RemoteException;
 import android.provider.Settings;
 
 import androidx.test.core.app.ApplicationProvider;
@@ -30,6 +33,8 @@ import androidx.test.ext.junit.runners.AndroidJUnit4;
 
 import com.android.settings.privatespace.PrivateSpaceMaintainer.ErrorDeletingPrivateSpace;
 
+import org.junit.After;
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -37,6 +42,7 @@ import org.mockito.MockitoAnnotations;
 
 @RunWith(AndroidJUnit4.class)
 public class PrivateSpaceMaintainerTest {
+    private static final String TAG = "PSMaintainerTest";
     private Context mContext;
     private ContentResolver mContentResolver;
 
@@ -48,6 +54,13 @@ public class PrivateSpaceMaintainerTest {
         mContentResolver = mContext.getContentResolver();
     }
 
+    @After
+    public void tearDown() {
+        PrivateSpaceMaintainer privateSpaceMaintainer =
+                PrivateSpaceMaintainer.getInstance(mContext);
+        privateSpaceMaintainer.deletePrivateSpace();
+    }
+
     /** Tests that {@link PrivateSpaceMaintainer#deletePrivateSpace()} deletes PS when PS exists. */
     @Test
     public void deletePrivateSpace_psExists_deletesPS() {
@@ -137,4 +150,52 @@ public class PrivateSpaceMaintainerTest {
         assertThat(privateSpaceMaintainer.getHidePrivateSpaceEntryPointSetting())
                 .isEqualTo(HIDE_PRIVATE_SPACE_ENTRY_POINT_ENABLED_VAL);
     }
+
+    /**
+     * Tests that {@link PrivateSpaceMaintainer#lockPrivateSpace()} when PS exists and is running
+     * locks the private profile.
+     */
+    @Test
+    public void lockPrivateSpace_psExistsAndPrivateProfileRunning_locksCreatedPrivateSpace() {
+        PrivateSpaceMaintainer privateSpaceMaintainer =
+                PrivateSpaceMaintainer.getInstance(mContext);
+        privateSpaceMaintainer.createPrivateSpace();
+        assertThat(privateSpaceMaintainer.doesPrivateSpaceExist()).isTrue();
+        assertThat(privateSpaceMaintainer.isPrivateProfileRunning()).isTrue();
+        assertThat(privateSpaceMaintainer.isPrivateSpaceLocked()).isFalse();
+        assertThat(privateSpaceMaintainer.lockPrivateSpace()).isTrue();
+        assertThat(privateSpaceMaintainer.isPrivateSpaceLocked()).isTrue();
+    }
+
+    /**
+     * Tests that {@link PrivateSpaceMaintainer#lockPrivateSpace()} when PS exist and private
+     * profile not running returns false.
+     */
+    @Test
+    public void lockPrivateSpace_psExistsAndPrivateProfileNotRunning_returnsFalse() {
+        PrivateSpaceMaintainer privateSpaceMaintainer =
+                PrivateSpaceMaintainer.getInstance(mContext);
+        privateSpaceMaintainer.createPrivateSpace();
+        assertThat(privateSpaceMaintainer.doesPrivateSpaceExist()).isTrue();
+        assertThat(privateSpaceMaintainer.isPrivateProfileRunning()).isTrue();
+        IActivityManager am = ActivityManager.getService();
+        try {
+            am.stopProfile(privateSpaceMaintainer.getPrivateProfileHandle().getIdentifier());
+        } catch (RemoteException e) {
+            Assert.fail("Stop profile failed with exception " + e.getMessage());
+        }
+        assertThat(privateSpaceMaintainer.isPrivateProfileRunning()).isFalse();
+        assertThat(privateSpaceMaintainer.lockPrivateSpace()).isFalse();
+    }
+
+    /**
+     * Tests that {@link PrivateSpaceMaintainer#lockPrivateSpace()} when no PS exists returns false.
+     */
+    @Test
+    public void lockPrivateSpace_psDoesNotExist_returnsFalse() {
+        PrivateSpaceMaintainer privateSpaceMaintainer =
+                PrivateSpaceMaintainer.getInstance(mContext);
+        assertThat(privateSpaceMaintainer.doesPrivateSpaceExist()).isFalse();
+        assertThat(privateSpaceMaintainer.lockPrivateSpace()).isFalse();
+    }
 }